Add the code snippets of the Kotlin String Template article (#4541)

core-kotlin/src/main/kotlin/com/baeldung/stringtemplates/Templates.kt

@@ -0,0 +1,115 @@
+package com.baeldung.stringtemplates
+
+/**
+ * Example of a useful function defined in Kotlin String class
+ */
+fun padExample(): String {
+	return "Hello".padEnd(10, '!')
+}
+
+/**
+ * Example of a simple string template usage
+ */
+fun simpleTemplate(n: Int): String {
+	val message = "n = $n"
+	return message
+}
+
+/**
+ * Example of a string template with a simple expression
+ */
+fun templateWithExpression(n: Int): String {
+	val message = "n + 1 = ${n + 1}"
+	return message
+}
+
+/**
+ * Example of a string template with expression containing some logic
+ */
+fun templateWithLogic(n: Int): String {
+	val message = "$n is ${if (n > 0) "positive" else "not positive"}"
+	return message
+}
+
+/**
+ * Example of nested string templates
+ */
+fun nestedTemplates(n: Int): String {
+	val message = "$n is ${if (n > 0) "positive" else if (n < 0) "negative and ${if (n % 2 == 0) "even" else "odd"}" else "zero"}"
+	return message
+}
+
+/**
+ * Example of joining array's element into a string with a default separator
+ */
+fun templateJoinArray(): String {
+	val numbers = listOf(1, 1, 2, 3, 5, 8)
+	val message = "first Fibonacci numbers: ${numbers.joinToString()}"
+	return message
+}
+
+/**
+ * Example of escaping the dollar sign
+ */
+fun notAStringTemplate(): String {
+	val message = "n = \$n"
+	return message
+}
+
+/**
+ * Example of a simple triple quoted string
+ */
+fun showFilePath(): String {
+	val path = """C:\Repository\read.me"""
+	return path
+}
+
+/**
+ * Example of a multiline string
+ */
+fun showMultiline(): String {
+	val receipt = """Item 1: $1.00
+Item 2: $0.50"""
+	return receipt
+}
+
+/**
+ * Example of a multiline string with indentation
+ */
+fun showMultilineIndent(): String {
+	val receipt = """Item 1: $1.00
+                        >Item 2: $0.50""".trimMargin(">")
+	return receipt
+}
+
+/**
+ * Example of a triple quoted string with a not-working escape sequence
+ */
+fun showTripleQuotedWrongEscape(): String {
+	val receipt = """Item 1: $1.00\nItem 2: $0.50"""
+	return receipt
+}
+
+/**
+ * Example of a triple quoted string with a correctly working escape sequence
+ */
+
+fun showTripleQuotedCorrectEscape(): String {
+	val receipt = """Item 1: $1.00${"\n"}Item 2: $0.50"""
+	return receipt
+}
+
+fun main(args: Array<String>) {
+	println(padExample())
+	println(simpleTemplate(10))
+	println(templateWithExpression(5))
+	println(templateWithLogic(7))
+	println(nestedTemplates(-5))
+	println(templateJoinArray())
+	println(notAStringTemplate())
+	println(showFilePath())
+	println(showMultiline())
+	println(showMultilineIndent())
+	println(showTripleQuotedWrongEscape())
+	println(showTripleQuotedCorrectEscape())
+}